Socio-Demographic Drivers of Residential CO2 Emissions in the 47 Prefectures of Japan

This study examined which socio-economic drivers contributed to energy-related CO2 emissions in Japanese households in all 47 prefectures since 1990. We adopted the logarithmic mean Divisia index technique to decompose the prefectural trends in CO2 emissions during the period 1990-2013 into six drivers: change in the number of households (household effect), distribution of households (distribution effect), household size (size effect), per-capita household energy consumption (consumption effect), household energy choice (choice effect), and sectoral CO2 emission intensity (technology effect). The results showed that, in contrast to the size effect, the household effect and the distribution effect both had positive and significant effects on CO2 emissions, indicating that these recent demographic trends were responsible for the increase in CO2 emissions observed in most of the prefectures during the period. Regarding the consumption effect and the choice effect, i.e., changes in CO2 emissions due to changes in lifestyle and technology, only ten and seven prefectures reduced their CO2 emissions in 2013, respectively. Thus, in order to further reduce CO2 emissions through these key drivers among prefectures, it is considered necessary to prioritize the transfer of new household energy technologies, upgrade household appliances, and encourage people to limit energy consumption.